Sprinkler control · backyard manifold

Sprinkler Valve Box

A two-course box of 1" × 5-3/8" deck boards over the 8-valve manifold, with a 6-board lid hinged at the back that hangs 1" past the front and both ends.

56 × 29¼"inside
58 × 31¼"outside
10¾"wall height
10deck boards
3aluminum braces
3⅝"room each side of the manifold

What it looks like illustration

The finished valve box with its lid open, showing the manifold inside

For the look only. It shows a center rail you're skipping for now, and the lid really hangs 1" past the front and both ends. Measure from the drawings below.

Top view lid off, to scale

manifold, about 45 × 22 58" outside 56" inside 31¼" outside 29¼" 5½ 3⅝ front is the bottom edge (the lid's 1" lip hangs over it)

The long front and back walls run the full 58". The 29-1/4" ends fit between them. Small 2" × 1" posts in the four inside corners tie the two courses together.

End view section through the middle, to scale

ground / gravel hinge 10¾" 1" lip lid 32¼" 5⅜"
No center rail for now. If the lid starts to sag, add one later: a 29-1/4" offcut fitted between the front and back walls at mid-length, top flush with the walls. Check the manifold's height first. On edge, the rail leaves 5-3/8" underneath; laid flat, it hangs only 1".

Lid underside to scale

back edge: hinges 6" middle brace on center 1" 60" 28"

The lid is 60" × 32-1/4": flush with the back wall (hinge side), 1" past each end and 1" past the front. Braces sit 6" in from each inside end wall plus one on center, each 5/8" clear of the front and back walls when the lid closes. Dashed line = where the walls land.

Cut list

PartSizeQtyFrom
Front / back wall pieces58"4boards 1–4
End wall pieces29¼"4boards 1–4
Lid boards60"6boards 5–10
Corner posts, ripped 2" wide10¾"4two lid offcuts
Aluminum angle braces28"3the 8 ft stick

Board layout 96½" boards, to scale

Boards 1–4 (each): one wall side + one wall end 58" 29¼" ~9" left Boards 5–10 (each): one lid board 60" ~36" offcut From two of the six 36" offcuts: 2 posts 10¾" × 2" (rip) 2 posts 10¾" × 2" (rip) Keep one offcut for a center rail (29-1/4") in case the lid sags.

Build order

  1. Cut everything from the cut list. Rip the corner posts to about 2" wide.
  2. Bottom course. Fit the 29-1/4" ends between the 58" sides and drive two 3" exterior screws through each side into each end. Check the diagonals match.
  3. Top course. Same again, stacked on the first. Screw a corner post inside each corner into both courses so they move as one.
  4. Set it over the manifold on the gravel, centered: about 5-1/2" clear at each end and 3-5/8" at each side.
  5. Lid. Lay the six 60" boards face down, butted and square. Screw the three 28" aluminum braces across them (pilot holes, pan heads, don't overtighten), placed as in the lid drawing.
  6. Hinge it to the back wall with the T-hinges: flush with the back, 1" past each end and 1" past the front.
  7. Watch for sag. If the lid dips in the middle, add the center rail from the spare offcut (see the end-view note).